Peptide phosphorodiamidate morpholino oligomers (PPMO) are synthetic DNA mimics that bind complementary RNA and inhibit bacterial gene expression. (RFF)₃RXB- AcpP PPMO (R, arginine; F, phenylalanine; X, 6-aminohexanoic acid; B, β-alanine) is complementary to 11 bases of the essential gene acpP (encodes acyl carrier protein). The MIC of (RFF)₃RXB-AcpP was 2.5...